Highly radioactive tea found in Fukushima City

The situation with tea in the Fukushima area is worrisome, to say the least. On March 23, the Mainichi newspaper reported (Japanese edition, English translation) that tea grown in the garden of a Fukushima resident last May 2011 measured 24,700 Bq/kg. That is 49.4 times the limit of the 500 Bq/kg set by the government. This is highly radioactive. Though the tea was not sold and there were bans on certain food products last year, that would not necessarily affect a private citizen’s use of tea grown in his/her garden. Needless to say, this person could have easily brewed the tea, unaware of the dangers. Fortunately he/she took it to the be tested (months later). Home gardens are quite common in rural and suburban areas, and school children all over Japan often go on trips to small tea fields to pick and later brew the leaves. They do the same with strawberries, potatoes and a variety of fruits and vegetables. Have school children picked and eaten local produce in the Fukushima City area? What about residents who have a garden in their back yard? Have any of them eaten from their gardens? What percent of local food is in the school lunches or adult diet?

Whilst one sample cannot be used to reach conclusions about the overall radiological contamination of gardens in Fukushima City, one must remember that this is not an isolated incident. In December 2011, “hot spots of up to 37 microSieverts per hour in a garden in suburban Watari,” reported Greenpeace (my emphasis). The data indicate that residents simply living in the area waiting for decontamination “are at risk of being exposed to over ten times the 1 milliSievert per year international maximum for radiation doses” (the range of 1mSv/year to 3mSv/year is usually considered normal background radiation, as per the NRC, which would still be 3 times over the limit). Greenpeace refers to the government’s effort to decontaminate as “incompetent,” and one that is “risking [the] health” of residents. There have been checks of background radiation, but what of the gardens? Would a blanket ban be appropriate? How would it be enforced? We do not know. But the government have banned food when much smaller levels were found last summer. The difference is this is not commercial, and hence unlikely to receive as much scrutiny.

In this picture taken in southern Japan in 2009, local residents are about to pick a Japanese radish. There are tea fields nearby where students pick tea regularly. Preparing local foods is usually part of the primary school curriculum. Stock photo, 2009, southern Japan.

A serious investigation of locally grown food might confirm the suspicion of widespread contamination (and it might not). That is, however, not what the Mainichi article says is going to happen. Instead, the authorities are asking individuals to voluntarily bring samples to a facility in future (not yet in service). The Mainichi says, “The city plans to increase the number of detectors and will set up 28 testing laboratories in the city by the end of this month.” This could be interpreted as saying there has been inadequate testing of food in Fukushima City for the past year, and that there is no plan to take preventive measures to stop the ingestion of possibly contaminated foods unless someone has the time to get his/her produce tested (not a quick process).

That such high levels have been found is hardly surprising in an area roughly 60km away from the power plant has high levels of radiation. To put it into perspective, the US government advised its citizens to evacuate to an area a minimum of 80km away from the plant. That means Fukushima City itself was considered so unsafe that Americans were told to leave or stay indoors; it goes without saying that food from the area would have been off limits.

The Japanese government never adopted those recommendations, and provides no compensation to residents in the area. How many people have consumed highly radioactive foods grown in their gardens in the past year? These are questions concerned parents have been asking themselves for some time now.